Update to using the latest default macOS and Xcode toolchain

Author: tonyarnold

.github/workflows/continuous-integration.yml

@@ -1,7 +1,7 @@
 name: Continuous Integration
 
 env:
-  DEVELOPER_DIR: "/Applications/Xcode_12.5.app/Contents/Developer"
+  DEVELOPER_DIR: "/Applications/Xcode_13.2.1.app/Contents/Developer"
 
 on:
   pull_request:
@@ -12,7 +12,7 @@ on:
 jobs:
   xcode-build:
     name: Xcode Build
-    runs-on: macos-11
+    runs-on: macos-latest
     strategy:
       matrix:
 
@@ -30,7 +30,7 @@ jobs:
 
   xcode-test:
     name: Xcode Test
-    runs-on: macos-11
+    runs-on: macos-latest
     strategy:
       matrix:
         destination: [
@@ -48,7 +48,7 @@ jobs:
 
   swift-package-manager-test:
     name: Swift Package Manager
-    runs-on: macos-11
+    runs-on: macos-latest
 
     steps:
     - uses: actions/checkout@v1
@@ -57,7 +57,7 @@ jobs:
 
   cocoapods-verify:
     name: CocoaPods
-    runs-on: macos-11
+    runs-on: macos-latest
 
     steps:
     - uses: actions/checkout@v1